Commit 1863accc authored by Eduard Zingerman's avatar Eduard Zingerman Committed by Andrii Nakryiko
Browse files

selftests/bpf: Test autocreate behavior for struct_ops maps 



Check that bpf_map__set_autocreate() can be used to disable automatic
creation for struct_ops maps.

Signed-off-by: default avatarEduard Zingerman <eddyz87@gmail.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240306104529.6453-8-eddyz87@gmail.com
parent c1b93c07

tools/testing/selftests/bpf/prog_tests/struct_ops_autocreate.c

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// SPDX-License-Identifier: GPL-2.0



#include <test_progs.h>

#include "struct_ops_autocreate.skel.h"



static void cant_load_full_object(void)

{

	struct struct_ops_autocreate *skel;

	char *log = NULL;

	int err;



	skel = struct_ops_autocreate__open();

	if (!ASSERT_OK_PTR(skel, "struct_ops_autocreate__open"))

		return;



	if (start_libbpf_log_capture())

		goto cleanup;

	/* The testmod_2 map BTF type (struct bpf_testmod_ops___v2) doesn't

	 * match the BTF of the actual struct bpf_testmod_ops defined in the

	 * kernel, so we should fail to load it if we don't disable autocreate

	 * for that map.

	 */

	err = struct_ops_autocreate__load(skel);

	log = stop_libbpf_log_capture();

	if (!ASSERT_ERR(err, "struct_ops_autocreate__load"))

		goto cleanup;



	ASSERT_HAS_SUBSTR(log, "libbpf: struct_ops init_kern", "init_kern message");

	ASSERT_EQ(err, -ENOTSUP, "errno should be ENOTSUP");



cleanup:

	free(log);

	struct_ops_autocreate__destroy(skel);

}



static void can_load_partial_object(void)

{

	struct struct_ops_autocreate *skel;

	struct bpf_link *link = NULL;

	int err;



	skel = struct_ops_autocreate__open();

	if (!ASSERT_OK_PTR(skel, "struct_ops_autocreate__open_opts"))

		return;



	err = bpf_program__set_autoload(skel->progs.test_2, false);

	if (!ASSERT_OK(err, "bpf_program__set_autoload"))

		goto cleanup;



	err = bpf_map__set_autocreate(skel->maps.testmod_2, false);

	if (!ASSERT_OK(err, "bpf_map__set_autocreate"))

		goto cleanup;



	err = struct_ops_autocreate__load(skel);

	if (ASSERT_OK(err, "struct_ops_autocreate__load"))

		goto cleanup;



	link = bpf_map__attach_struct_ops(skel->maps.testmod_1);

	if (!ASSERT_OK_PTR(link, "bpf_map__attach_struct_ops"))

		goto cleanup;



	/* test_1() would be called from bpf_dummy_reg2() in bpf_testmod.c */

	ASSERT_EQ(skel->bss->test_1_result, 42, "test_1_result");



cleanup:

	bpf_link__destroy(link);

	struct_ops_autocreate__destroy(skel);

}



void test_struct_ops_autocreate(void)

{

	if (test__start_subtest("cant_load_full_object"))

		cant_load_full_object();

	if (test__start_subtest("can_load_partial_object"))

		can_load_partial_object();

}

tools/testing/selftests/bpf/progs/struct_ops_autocreate.c

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// SPDX-License-Identifier: GPL-2.0



#include <linux/bpf.h>

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>



char _license[] SEC("license") = "GPL";



int test_1_result = 0;



SEC("struct_ops/test_1")

int BPF_PROG(test_1)

{

	test_1_result = 42;

	return 0;

}



SEC("struct_ops/test_1")

int BPF_PROG(test_2)

{

	return 0;

}



struct bpf_testmod_ops___v1 {

	int (*test_1)(void);

};



struct bpf_testmod_ops___v2 {

	int (*test_1)(void);

	int (*does_not_exist)(void);

};



SEC(".struct_ops.link")

struct bpf_testmod_ops___v1 testmod_1 = {

	.test_1 = (void *)test_1

};



SEC(".struct_ops.link")

struct bpf_testmod_ops___v2 testmod_2 = {

	.test_1 = (void *)test_1,

	.does_not_exist = (void *)test_2

};